Grinding machine



May 24,1932. .W.J.GUH D 1,859,737

GRINDING MACHINE Filed May 25, 3.928

2 Sheets-Sheet l wad@ I. umm

May 24, 1932 w. J. GUILD 1,859,737

GRVTNDING MACHINE Filed May 25, 1928 2 Sheets- Sheet 2 5 wam@ J. Gum

Patented May 24, 1932v UNITED STA TES PATENT OFFICE WALDO J. GUILD,OFWORCESTEB, MASSACHUSETTS, ASSIGNOR T THE HEALD MA- CHINE COMPANY, OFWORCESTER, MASSACHUSETTS, A CORPORATION 0F MASSA- cnusnm's enINmNeMACHINE l Application led May 25,

The invention, which isan improvement on an invention lof Carle J.Highberg, as.

shown in a copending application Serial No. 266,287, filed March 31,1928, relates to in.- A 6 ternal grinding machines and particularly tothe Work holding and Work rotating mechanism thereof. The presentinvention is shown applied to a grinding machine that is manuallycontrolled, but it shouldv be understood that it can equally well beapplied to an automatic machine in which the grinding operation isautomatically terminated when each workpiecehas been ground to thedesired internal diameter. The present invention utilizes the centerlesswork holdim?.r means of the Highberg invent-ion.

More specificallyv the present invention contemplates a simplificationof the aforesaid ccnterless work holding means by giv- 20 ing directlyto one or more of the idler rolls that constitute said means thecross-feed movement that causes the grinding wheel to cut deeper intothe workpiece, instead of feeding the work head as a whole or the wheelhead in relation to the work head.

The invention further contemplates an arrangement of the work holdingand work rotating rolls whereby workpieces can be very easily placed ingrinding position and ejected or removed therefrom.

The above and other advantageous features of the invention willhereinafter more fully appear from the following description which,taken in connection with the accompanying drawings, constitutes anillustrative embodiment of the invention. In the said drawings Fig. 1 isa front elevation of a grinding o machine .embodying the invention.

Fig; 2 is a plan view of the machine.

Fig. 3 is an end eleva-tion of the machine taken from the left-hand sideof Figs. 1 and 2.

Fig. 4 is a fragmentary view of the work rotating roller detached fromthe machine, showing it in the position in relation to its supportingbracket inwhich it ejects a worknece.

l Fig. 5 is al fragmentary view of the trans- 1928. Serial No. 280,609.

verse feeding roller and bracket. v

Like reference characters refer to like parts throughout the drawings.

Referring first to Figs. 1 and 2, an internal grinding machine is shown,having a reciprocatory table or carriage 1 by'ithe reciprocation ofwhich the grinding traverse is produced. The table l in this instancecarries a Wheel head2, which ismounted on an interposed cross-slide 3,the latter being provided in order to allow of a periodic transversemovement of the grinding wheel 4 in relation to the Work head of themachine to compensate for wear on--said grinding wheel. It should beunderstood, however, that such compensating means forms no part of the.present invention.

rlhe grinding wheel 4 is mounted on a spindle 5 which is journalled inthe usual its supporting `manner in the Wheel head 2;-the spindledriving means which causes rapid rotation of the grinding wheel need notbe herein described, as such is well known in this art, and any suitableform thereof may be provided. Similarly, the aforesaid reciprocatingmotion of the table 1, to cause the rotating grinding Wheel 4 to makethe required interior traverse of a. workpiece, may be imparted in anywell known manner, but as illustrative of a specific embodiment of such,reference should be had to United States Letters Patent No. 1,582,468,granted April 27, 1926, to Heald and Guild, which shows fluid pressureactuating and reversing mechanism to produce the aforesaid traverse.

The table 1 carries a pair of spaced ad-A justable dogs 6 and 7 whichare adapted to alternately engage and move a reversing member 8, theseparts constituting the controlling means of the aforesaid actuating andreversing mechanism. By means. of a hand lever 9 the direction of travelof the table can be-controlled independently of the automatic actuationabove set forth, while an inclined arm lisupported by a vertical rod 11on the front of the machine, and adapted to be raised when the operatorsteps upon a treadle 12, will cause the reversing dog 6, which ispivotally mounted on its adjustable carrying block 13, .to be liftedclear of the reversing member 8, whenever the operator desires tointerrupt the grinding. In Athis manner the work and wheel can beseparated at any time for the purpose of dressing the grinding wheel 4bymeans of a dressing device 14, or in order to allow the operator toremove the ground workpiece and place an unground workpiecey 1n themachine.

Referring to Figs. 1, 2 and 3, a bridge 15 is attached to the machineframe and spans the ways 16, 16 which support the table 1, thus allowingsaid table to move thereunder. This bridge V provides an upwardlyextending frame portion 17 which supports the work' holding and workrotating means, and

the` cross-feed mechanism therefor. Said work holding and work rotatingmeans comprises three tangential work supporting rollers 18, 19 and 20.The roller 18 constitutes the bottom support for a workpiece a and isstationarily mounted on a stud 21 projecting from the frame portion 17The roller 19 constitutes one of the side supportssiliently supported byspring means in order to hold the workpiece in position, yet to allow ofthe advance of the roller 19.

Still referring to the same figures, the frame portion 17 provides anupwardly projecting portion 17a. Said portion has a horizontal holetherethrough, which constitutes a bearing support for a screw,shaft 24.A ratchet wheel 25 is mounted on, but not fastened to, the. forwardlyextending portion of this shaft, while in front of the ratchet wheel isa hand wheel 26 that is fastened to the shaft. Between the hand wheeland the ratchet wheel is a compressible washer or friction pad 27. Bymeans of a collar' 28 onone side of thebearing portion Y 17 a, and a nut29 screwed on to the threaded front end of the screw shaft 24, theseparts can be drawn together on the screw shaft,

thus eliminatinor end motion of the shaft in relation to its bearingsupport and, at the same time, providing a friction drive for the screwshaft through the ratchet 25, the pad 27, and the hand wheel 26. Thenonpositive form of drive is desirable for a reason that willhereinafter appear.

The screw shaft 24, as best shown in Fig. 5, extends through aninternally threaded member 30 which` ,as shown in dotted lines in saidfigure', provides a grooved projecting portion 31 that-is held fromlongitudinal displacement in a hub 32 of the arm 23, by means of a pin33 fitting in the said groove. This connection, while keeping the partstogether,

allows the member 30 complete freedom of angular movement relative tothe hub 32 and the arm 23. The arm 23 is pivotally attached at 34 to theframe portion 17, and rotation of the screw Vshaft 24, therefore, movesthe roller 19 in relation to the machine frame. It should be observedthat such movement, which causes the grinding wheel 4 to grind aworkpiece ato size, is actually a very small one, so that there ispractically no rise and fall of the member 30 which will interfere withits actuation bythe screw shaft 24 that is in al substantially fixedhorizontal position. If it is' desired to grind -a substantiallydifferent size of workpiece a, a roller 18 of different diameter may besupplied, and for the adjustment of the center of this roller, and alsoof the pivotal center of the movable Varm 23, slots 21a and 34arespectively are provi-ded in the frame 17.

The slot under roller 18 is at an angle of 45 so that the movement willbe out and down at the same time, while the slot under the armcarryingthe roller 19 is in a horizontal plane for adjustment outward. By thisarrangement, the drivin'g roller 2O can remain in its original positionon the same lhorizontal plane as the center of the grinding wheel.

The cross-feed screw shaft 24, which advances the roller 19 asdescribed, is automatically turned by an intermittently actuated pawlengaging the ratchet wheel 25, and may be manually turned, to eitheradvance or retract the roller 19, by means of the hand wheel 26. Asshown in Figs. 1 and 2, the table 1 carries a forwardly projectingbracket 35 which, at the end of the inward travel of veach workingstroke of said table, strikes and moves a rod 36. The latter ispivotally attached at 37 to a depending arm 38a carried by a yoke orcollar 38 that surrounds a hub provided by the ratchet wheel 25. The rod36 is also slidably received by a projecting'boss 39 formed on t-hebridge 15. Movement of the rod 36 by actuation from the table 1,consequently, oscillates the yoke 38 and the depending arm 38a, therebeing a spring 40 to return the partsrto the osition shown in Fig. 1 atthe end of eac clockwise oscillation of these parts. Carried by thedepending arm 38a on the aforesaid pivot stud 37 is a pawl 41 which, bymeans of a spring pressed plunger carried inside thereof and a detent inthe cylindrical surface of the stud 37,

is resiliently held in the position relative to vthe arm 38a that isshown in Fig. 1, it being understood that the pawl 41 may be deflectedupwardly againstv the pressure of the said spring. These parts are notshown in detail because they are very small and are well known in theart for the spring actuation of pawls. When the pawl 41 is moved to theleft in Fig. 1, by the oscillation of the arm ICG were? f 38u,` asalready. described, an inclined surface v42 on, said pawl strikes a cammember 43 provided by an arm` 44, that is pivotally mounted at 45 to theframe 17 This action forces the pawl 41 inl a clockwise` direction onits pivot stud 38 causing engagement, of

a pawl tooth 46 with lthe ratchet, wheel 25.

The position of the cam member A43 relative to the pawl 41 is adjustableby means of a screw 47 carried on a projecting portion of the frame 17,Said screw engaging Aan arm 48 that is integrally attached to thearm 44.

`A spring 49-is provided to draw the-arm4`8 to the adjustable screw 47.Adjustment. of the positior'of the `cam member 43of course, regulatestheangular distance through which the ratchet wheel will be movedoneachactuation 'by the pawl 41.

- Means being thus provided to delicately feed one of the tangentialsupporting rollers as just described, it is obvious that the feed.' Atthe same. time a certain amount` 'so that it ma oppositelydisposedtangential roller, in .this case the roller A20', must beresiliently held I give waybefre the advancing roller, or there couldnot be any cross- `of pressure must be exerted against the workpiece orit will not be heldin grinding posi- 36 tion or rotated by the roller20. To that end' the roller 20 is rotatably mounted on a shaft 50 thatis held by avforked bracket 51, the latter being supported by an arm 52that `is -pivotally mounted on the frame 17 at 53, counterclockwisemovement of these parts being resisted by a spring 54. It will beobserve from Fig.- 3 that the pivot stud 53 is locat d substantiallybelow the shaft 50, and thus in the limited cross-feed movement of theworkpiece a as given it by the mechanism already described, theresultant` movement of the roller 20'wil14 be almost, if not quite, in ahorizontal., plane. In order to limit the movement of the v1'iollefrl'20in a' clockwise direction when no vworkpiece 'a is in the' machine, ascrew 55 screwed'into the arm 52 is provided, this screwY passingthrough a lug 56y provided on the rear of the frame-'portion 17,'a nut57 also being pref;

erably provided to adjust the initial position of the lroller 20.

In order to rotate the workpiece, rotation is imparted to one or more ofthe three rollers 18, 19 and 20. In; this embodiment of the inventionthe roller 20 is the' driving roller, vand therefore it is provided'with an integrally formed pulley portion 20a, around which adrivingbelt, nt shown, passes. In order that each 'imn-kpiecev may beheld 6ofromlongitudinal movement; the axisof r6- to the axis ofworkpiece rotation,during'the tation of the roller 20 is inclined with4respect j grinding operation.f "1`hat is to say, assumingthe axis ofrotationofthe workpiece lto be horizontah'theaxis of the shaft 50, andconsequently also-.that of the roller 20, when vice provided to holdthem successive said workpiece is being ground, is inclinedto'thehorizontal. Assuming the roller to be: rotating inthe-direction ofthe small arrows, Figs. 2 and '3, which is the case, this inclinationVgives the workpieces an end thrust tothe right Figs. 1 and 2,-whichcauses them to be pressed against a positioning degrinding position.

This positioning device comprises a rotatvin able annular ring 58, whichis mounted in ball bearings 59 provided by an annular stationary. member60 that projects upwardly -fromthe/bridge 15. and which serves at oncefor the supportgof'said ring and its ball bearings and as a guard toprevent the o rator of the machine from being injuredyliy the grindingwheel. The rotatable rin 58 interferes in no wise with the passage o the'grinding wheell therethrough to reach a workpiece, but serves t'o holdsuccessive workpieces in accurate longitudinal position a ainst thecombined force of the tractive e ect of the grinding, wheel when movingoutwardly in its reciprocatory traverse, and

the thrust imparted by the inclination of the axis ofthe roller 20 tothe axis of' rotation 'of the workpiece. The means just described forkedmember 51 isnot integrally attached- Ato the l arm 52,-. but ispivotally mounted thereon by means lof a' shaft 62 rojectingrearwardly-from said forked mem r. Said.

shaft -isthreaded for a nut asv shown, andv extends through a hubportion 63 formed on the arm 52. `The forked membercp'rovides a pair ofdepressions 64 and 65 on its at rear surface, and a projection 63a onthe side of the hub 63contains a spring 66 which presses a .ball 67forwardly to engage one of these 'depressions inthe forked member V'51.Thus said forked member is resiliently held with the axis of the roll 20inclined to the axis of rotation of' a workpiece in either onef'of twoositions, which are illustrated respectively y Figs. 1, 2, and 3 on theone hand,v and Fig. 4 on the other hand, the former being Athe grindingposition, and the 4latter awork ejecting position.

A'liandle 68 is provided by the forked member 51. When a given workpiecehas been 'ground and the grinding wheel 4 has been withdrawn therefromby movement of the table 1 to the right, Fig. 1, brought about,

by example, by depression of the treadle 12, the operator m'ay cause thefinished workpiece to be ejected from the machine by depressing thishandle. The relative compressive forces of the springs 54 and 66, asmodified by the effective leverage and inclined is now to the left, andthe workpiece will be ejected from the machine. being received by anysuitable receptacle or chute, not shown.

The finished workpiecehaving been ejected, the operator should raise thehandle 68 and return the parts to the position shown in Figs. 1 and 2.I-Ie may then place a new workpiece in grinding position by merelypresenting it from above to the rollers 19 and 20. If it does notimmediately snap into position, the operator may move the roller 20bodily away from the roller 519 by depressing the arm 52, and this maybe done without again disturbing the inclination of the axis of theroller 20 by pushing down on the hub 63. But if desired, the axis of theroller may be temporarily made horizontal, while loading, therer beingunder such condiions less tendency for the workpiece to tip over ortwist out of position.

Although, as previously stated, the apparatus of the present inventioncan be readily applied to any of the several forms of automatic grindingmachines now known toY the art, being particularly adapted for use inconnection with that class of machine in which the control of the sizeof the workpieces is maintained by devices operated by the position ofthe cross-feeding mechanism,

a dressing device and compensating means being employed to insureuniform size, all as disclosed in my own'prior and copending applicationSerial No. 48,734, filed August 7, 1925, now Patent No. 1,682,672,granted August 28, 1928,y I have shown in the present drawings a stop tocause cessation of the cross-fed when the workpiece reaches desiredsize, leaving it to the operator to cause withdrawal of the wheel fromthe workpiece. As shown in Figs. 2, 3, and 5, the arm 23 provides a boss69 which is internally threaded and which holds an adjustable screw 70that can be locked in an means of a chuck nut 1. The left-hand end, Fig.3, of the screw', when the grinding operation is completed as determinedby the proper setting given to said screw 70, is adapted to engage aprojecting portion 72 provided by the frame 17 and thus positively stopthe feeding mechanism. Subsequent actuation bythe reciprocating table 1of the cross-feed'pawl 41, with consequent turning of the ratchet wheel25 will not turn-the screw desired position by therefor.

It should be noted that the loading and unloading of workpieces whichhas been described somewhat at length, can be manually performed in muchless time than it takes to tell about it. In fact the operator may,after the grinding wheel 5 has been withdrawn from grinding position,grasp the lever 68 with one hand and a fresh workpiece with the other,depress the handle, thus ejecting Va workpiece, raise the handle 68,depress the arm 52 and place an unground workpiece in position, inl avery short space oftime. It will be noticed that the operator hascomplete freedom of access to the Workholding mechanism from the lefthand side thereof, which is the side away from the grinding By thisadvantageous feature of construction, there is no danger to theoperators hand from the rapidly rotating grinding wheel 5.

It is within the contemplation of my invention that automatic means maybe provided to change the inclination of the axis ofthe roller 20, asset forth, and also to move it in relation to the rollers 18 and 19 asdescribed. The several sets of movements being regular and occurring atpredetermined times in relation to the position of the table 1 on themachine base, cam means may be provided by said table. to perform thesefunctions, and then by the provision of a work holding magazine andescapement devices of any suitable type, of the general nature shown inthe aforesaid copending application of Highberg, for example, themachine would be completely automatic so far as the work loading isconcerned.

While it is not the intention to claim any instrumentalities not shown,in construing the claims hereto appended those elements of the machinewhich are now manually controlled and operated may be considered to beeither such or automatically and mechanically operated. The above andlike changes, falling within the spirit of the invention are to beconstrued as included in the claims.l

I claim,

1. In a machine of the class described, the combination with a pluralityof work holding and work-rotating rolls, of a driving roll, a pivotalmounting for said driving roll whereby it may 'be caused to approachtowards or recede from the other rolls for the insertion or discharge ofa workpiece, and a further pivotal mounting for said roll whereby saiddriving roll may be inclined to the axis of rotation of a workpiece toproduce an end thrust on the latter, or placed in parallelism therewithto facilitate loading of workpieces.

2. In a machine of the class described, the combination with a pluralityof work holding and work-rotating rolls, of automatic feeding means.lassociatedlwith one of said rolls to feed it and therefore the workpiecein cutting relation to a grinding wheel.

3. In a machine of the class described, the combination with a roll andmeans to feed it, of another roll and spring means to back the latterroll up, whereby the workpiece may be held in grinding position and'fedto produce a cutting advance between workpiece and grinding wheelwithout the use' of a chuck.

4. In a machine of the class described, the combination with a workpositioning roll, means to feed it, and a grinding wheel, of a table orcarriage by the reciprocatio'n of which a grinding traverse is produced,and means derived from motion of said carriage to actuate said feedingmeans.

5. In apparatus of the class described, a pivotally mounted arm, a rollconstituting one of centerless work holding means on the end of' saidarm, an internally threaded member connected by a swivel to said arm, ascrew shaft passing through said member and automatic means to feed saidscrew shaft, whereby to feed said roll to produce the cutting advance ofa workpiece.

6. In a grinding machine, the combination with a plurality of workholding and work rotating rollers, of a rotatable annular member, adriving roller that is normally skewed with respect to the axis of theother rollers, whereby to give the workpiece an end thrust to hold itagainst said annular member, and means for altering the inclination ofthe axis of said driving roller to eject a workpiece from the machine.

7. In an apparatus of theclass described, a frame for the holdin of a.plurality of rollers for the centerless grinding of workpieces, abracket pivotally mounted on said frame, a forked member holding one ofsa1d rollers pivotally connected to sald bracket, and means for holdingsaid forked member in two end positions to give said roller aninclination to the axis of a workpiece to hold it in centerless grindingposition or eject it therefrom.

8. In an apparatus of the class descrlbed, in combination, a roll, meansto feed said roll to produce a relative cross feed between a workpieceand a grinding wheel, a spring pressed roll mounted opposite the firstnamed roll, rotating means for one of said rolls, one of said rollsbeing inclined with respect to the workpiece, and a third supportingmeans for the workpiece.

9. In an apparatus of the class described, the combination with a roll,means to feed said roll to produce a relative cross feed between aworkpiece and a grinding wheel, a

spring pressed roll mounted opposite the first named roll,prota tingmeans for one of said rolls, one 'of sind" rolls being inclinedworkpieces.

WALDO J. GUILD.

